I used this guide for disassembling a K750i:Originally Posted by a9ballbr8k
It's pretty much the same as the W810i.
It's not difficult. If you've ever added ram to a laptop you've done half the job. The toughest part for me was just getting the front plate off without forcing anything.
The whole job took me at least a couple of hours I think, but I was very gentle and meticulous.
Oh, and the guide doesn't mention how to get the mem stick cover off. It has a sort of arrowhead that sticks through a slot in the middleplate. Compress it from one side with a flat screwdriver and you can pull it out.
Since you'll be using the back and middle from the K750i, you won't have to mod the middleplate to make it fit the back, however the front plate matches the 750 middle only 99%. You will have to make a little notch in the middle plate at the top near the power button to accomodate a tiny flange on the 810 front. It's no problem. In fact, I couldn't find my exacto, so I did it with a steak knife and it was still dead simple, and as long as you dont let the knife mar the ******d facing edge you can butcher the inside edge and noone will ever see it.
One potential drawback of the 750 middleplate is that it doesn't have the walkman logo on it. Someone on this board has a hybrid with a silver middleplate that does have the logo, but I'm not sure which phone it came from.