I just finished installing a 1GB stick I purchased from macsolutions.com. It was very easy to open up and install.
I picked up a very flexible 1.5" putty knife. I would not use one if it's not flexible because I think it would increase the possibilty of damaging the case. The first thing to note from my expirience is the putty knife does not go very far down when inserting it. Basically there is a lip on the case that stops it so do not force it down too far. The first side was much harder to lift than the second side. Take your time and switch to the other side if it's not giving. Note that there is some kind of braided cable tape that goes along the lip. You will damage this with the putty knife and I'm not sure why its on the case. To minimize damaging this, do not slide the knife back and forth once in place. Once the back is opened slightly, it pulls right out. Installing the ram was a piece of cake.
Now putting it back together was a little harder. I figured I'd line it all up and snap it down leaning a little towards the front first. The back was the first side out so it should be the last side in, right? Nope. The metal EFI clips didn't line up. Everything else snapped into place but the back did not come down. After about three trys, I went with the back snapping in first while making sure the clips stayed behind the case top. Then I snapped down the front side.
The back panel now may be a little more squishy than I recall but I really didn't take notice before. I suspect that one or two of the clips are a little bent and are not applying as much pressure to the back as the did.
I'd be interested in anyone elses comments that performed this and I'll try to answer anyone else's questions if they ask...

I picked up a very flexible 1.5" putty knife. I would not use one if it's not flexible because I think it would increase the possibilty of damaging the case. The first thing to note from my expirience is the putty knife does not go very far down when inserting it. Basically there is a lip on the case that stops it so do not force it down too far. The first side was much harder to lift than the second side. Take your time and switch to the other side if it's not giving. Note that there is some kind of braided cable tape that goes along the lip. You will damage this with the putty knife and I'm not sure why its on the case. To minimize damaging this, do not slide the knife back and forth once in place. Once the back is opened slightly, it pulls right out. Installing the ram was a piece of cake.
Now putting it back together was a little harder. I figured I'd line it all up and snap it down leaning a little towards the front first. The back was the first side out so it should be the last side in, right? Nope. The metal EFI clips didn't line up. Everything else snapped into place but the back did not come down. After about three trys, I went with the back snapping in first while making sure the clips stayed behind the case top. Then I snapped down the front side.
The back panel now may be a little more squishy than I recall but I really didn't take notice before. I suspect that one or two of the clips are a little bent and are not applying as much pressure to the back as the did.
I'd be interested in anyone elses comments that performed this and I'll try to answer anyone else's questions if they ask...