1st,remove all your parts as usual.

2nd,get your drill,rivets and riveter ready.

3rd,take out all those rivets that is needed to remove the parts you want to convert.Make sure the drill bits you use is not too.It will make the holes for rivets grow bigger.

4th,convert you back part of the case to BTX.Make sure all the rivets holes are in place.If its not in place,make a new holes by using a drill.

5th,if all holes done,get start to install the rivets back to their positions.

6.There you go.DONE!.

Good Luck.