I took one apart and put the good cover from one with a damaged screen onto the one I had with a scuffed cover.
It was successful but a real pain in the butt.
Take off back cover/battery cover. and unscrew the screws you can see.
Next bit is the hard bit and I just did it by brute force, but you then need to take off the white pearly bit around the camera, as other screws are hidden under there. I just used a small screwdriver and edged my way around the top, but it was pretty firm and took some getting off.
Once that was off, I undid two more screwsand that allowed me to edge off the black section where the battery sits from the main phone bit (green computery hardware bit

sorry, I'm not very techy!! ) I again did this slowly but it needed some force as it's very very snugly fitted. There are some black clips as part of this middle section that you can push inwards to release the front with screen and keyboard and reveale the phone inards.
You immediately notice the ribbon attaching the camera to the main motherboard/phone and it pops out . I then unscrewed the 4 tiny tiny screws attaching the screen to the frontof the phone and very gently prised the whole phone guts out and immediately dropped it onto the new front I had ready. Screwed the screen back in place and also one other ribbon plugs into the motherboard from the keyboard Front section.
Trickiest part was re screwing the screen screws as they were teeny and I had to use tweezers to hold em in place. Then replugged in the bottom ribbon (Think it was power button? ) and placed the battery section back on top of the motherboard bit.
Another tricky bit was re attaching the ribbon from the camera as I had to almost close the black battery section and just leave a tiny gap and use the flat end of my tweezers to gently push the ribbon connector in. It's doable but bloomin fiddly.
After that I clicked as much of the battery/middle section back onto the front/screen and keyboard section, but inevitable it's not quite as fixed as it was, and there are signs that it's been taken appart as I found it impossible to take appart with out some force and some of the plastic clips were either bent ir broken in doing it. I screwed the screws back on and put back the white section round the camera - luckily everything started up and worked OK, but I'm sure I could have easily messed it up
Its a very fiddly thing to attempt. I only did it as I'd got two handsets reasonably cheaply and wasn't risking much. But it's a phone that obvioulsy wasn't made with cover changes in mind. LOL Once fully put together again it's robust and no loose bits, and everything working fine.
Daisy xx