It's my experience that no matter how you do it, removing tiles from plasterboard walls, is that lumps of adhesive get left on or the plaster skim comes off or both. Re-skimming such a damaged wall can be difficult for the amateur and obviously expensive to get a professional in. Considering that tiling is generally a long term wall covering and plasterboard is relatively cheap, re-boarding as Dave the Medway Handyman suggests is in my eyes a more favoured option especially when you consider it's adhesion qualities as mentioned in my previous post.

Richard