Not seen one of those, but I think the main thing is to watch out for a little spring and ball bearing or detent pin if the rotating part has click-stops - if any of those ping across the room, they're as good as lost. The click-stop parts could be captive, but that's unknown unless documentation can be found or the thing is actually dismantled, so care must be exercised.
If you haven't done anything like this before, you should first consider whether it's within your capabilities. You do need a steady hand and some mechanical aptitude (it shouldn't be complicated mechanically). Consider taking digital photos as you take things apart to remind yourself of the arrangement of bits when you reassemble.
Use screwdrivers which are a good fit to the screws. Don't use excessive force to slacken or tighten. Use fine-tipped tweezers for handling small parts. A loupe is very good for examining both the parts and the state of the glass surfaces. Work in good light, on a tray on a table top so that anything that gets dropped and slides along the work surface will have a boundary to stop it going further. Lay a sheet of paper towel on the tray - this will help stop things bouncing around if they get dropped. A small plastic box with multiple compartments is good for holding small parts while you work. Maplin do one with multiple lids, meaning you only need to open one compartment at a time, meaning you don't spill the rest if you bump it while dropping a part in or taking a part out.
Count any parts that are multiples as you take them off. Note any differences in screws, eg, long screw at the top and short screws at the rest, shoulder screw here, or whatever.
Be very careful when handling any glass with silvered surfaces (mirrors or prisms). Avoid touching the silvered surfaces with your fingers. Restrict wet cleaning of these to lens cleaner only - avoid strong solvents.
For cleaning greasy and oily mechanical bits, lighter fluid is pretty good, applied either with a bit of paper towel or a small paint brush (I use a stiff bristle flat brush about 5mm wide). Check for potential damage to finish by wetting a bit of paper towel with the solvent, and rubbing gently on a small area that's generally out of sight - if the paper picks up the finish, either use a different solvent or take care to keep it away from the vulnerable finish. If cleaning near glass, avoid getting solvent on the glass itself, or dismantle further if possible. Remove lumps of gunk using cocktail sticks - they're benign on softer metals like aluminium. Apply new grease or oil using a cocktail stick for tiny amounts (or a small soft bristle brush for larger amounts of oil). Usually tiny amounts is all that's needed - the lubricant only needs to be on the surfaces that actually make contact with each other. Bear in mind that oil can migrate and potentially get onto glass surfaces. I would probably use grease for this (I have Teflon grease made by a brand called StarBrite - very high spec and benign on plastics).
For cleaning the glass, blower first to remove loose dust, then a soft brush for more stubborn bits, followed by blower again. After that, microfibre cloth and lens cleaner to remove the more stubborn stuff - apply fluid to cloth only - don't squirt it directly onto the part (it's mostly water, and flooding could lead to corrosion later). Asda spectacle cleaning cloths and fluid are fine and are way cheaper than supposed photography stuff (ie, cheap enough to get filthy and not worry, and won't do any harm). Have a wet corner and a dry corner on the cloth - wet wipe first, and then a gentle buff with a dry bit. Avoid reusing bits of cloth that get dirty - move to new bits or use another cloth (they're only a quid each, so get 2 or 3). Look through each bit of glass with a loupe - move the part forwards and backwards to check for dust and crud on both surfaces. A computer monitor showing white is a good backlight for this. Look at each surface with a loupe using reflected light to check for smearing. If there is smearing, do another wet clean and buff, Getting right in at the edges of the glass can be tricky and not getting those bits really clean won't adversely affect the optical performance, so don't belabour that unless you want to.
Reassemble using the minimum amount of lubricant needed. All moving parts should feel smooth and slick unless they were poorly machined to begin with or have been damaged in some way. One final blow on each glass surface as you reassemble in case new dust has arrived (better than taking it apart again). Count the parts as you reassemble, reminding yourself of any that were different and where they go. Refer to digital photos if needed. When assembled, twiddle the mechanicals to make sure they all feel correct, and look through the optics to verify that they do what's expected (ie, correct magnifications at indicated settings, images are clear and sharp, definitely no annoying bits of dust).
If it all looks good, congratulate yourself.
