How to replace faceplate, backplate and side buttons frame?

I have recently bought a replacement set of faceplate, backplate and sidebuttons frame for my Ol' Trustworthy Nokia 5630, to fix the + and - volume buttons on the side that I lost some time ago. I found out that the sidebuttons frame also carries the flash circuit and connector, both of which are not included in the newly bought (as described, no electronic parts included). I do not dare to remove it from my old frame without some aid.

Any advice?

(The part that I bought is http://www.dhgate.com/product/for-nokia-...)