Fireplaces, Heating Stoves, Flues and Chimneys - replacing slate with marble

I have a pre-fab fireplace with a black slate hearth. I have bought marble to replace the black slate. Now the fun starts...

From what I understand, the slate is 'glued' to the drywall. What is a good technique for removing the slate?

Also, any tips on installing the new marble would be appreciated.

Thanks

Hello
first of all take a box knife and cut the paper all the way around the slate...after you cut the paper....use wood long thin wedges made from a 2x4 3/4" to a point about 12" long.. find the studs and drive a wedge at each stud when you have all the wedges in start to drive them in a little at a time untill the slate come loose from the wall....if this is not working very well...take a hammer and break the slate into smaller peices remove the peices one by one this is much easyer than trying to remove one big peice...if it takes the paper off of the dry wall where you cut it will stop it from going out passed where the slate is....clean every thing up and fit the marble when every thing is fitted
install with mastick from the bottom to the top and side to side......Good luck