Keith,
Its not all that hard to do but you need a little equipment and need to do it on the right sequence. Thats about it. Anyone with basic mechanical skills should be able to do it with a little patience.
There is (was?) a very nice video on YouTube which explains how to remove the cover from the M6 (I think there may also be one on the earlier cameras too). In any event the M2 is basically identical to the M6 with the exceptions that there is an extra screw at the top dead centre position in the lens mount and of course the rewind knob is different.
I had a quick look on Youtube today but could not see the video again. (You may wish to search yourself using top cover, top plate and similar search terms.) However I have the video downloaded to my PC - Private Mail me, Keith and I will send it too you.
This thread on Photnet may also help.
http://photo.net/leica-rangefinders-forum/0053Vp
As may this thread (on RFF) where we discussed the tools needed for getting the top off an M4P to replace a faulty flash sync plug (a problem that M4Ps sometimes develop as they get older. Incidentally anyone wants a complete M4P flashblock - I have one I bought on eBay but have not now used. It cost me $70 and I would let it go for that.)
http://www.rangefinderforum.com/forums/showthread.php?t=82826&highlight=leica+top+plate
I also have the two most essential clamps which I no longer need (a further clamp is optional and you will see why if you watch the video). They are not expensive if you get them from the right source as I did so I am sure that we can work something out if you wish - have to look after another Aussie. (I have sold my M4-p and bought an M8 so do not anticipate requiring these again.) From memory if you buy them as a set specifically for Leica they charge more than if you buy them individually. Problem is that in the latter case you need to know the correct sizes to order. (See the above thread which informs you of the correct sizes)
Incidentally I checked with my camera guy when I was preparing to clean my finder - he told me as did another knowledgeable person that camera tech's clean the inside of the window with toothpaste. I did not need to do this as in the end the opportunity to buy an M8 came up at a good price so I sold my camera instead.
So I cannot vouch for the toothpaste technique but it may be something you wish to make further inquiries about. (Or experiment with if you are game - although I have faith in the guys who told me this.)