I've just had to make use of Navitotal's Tutorial on disassembly of the x20/x30 to replace the original battery in my 730 and figured that the following additional advice might be useful for anyone doing the same:
Instead of risking severe damage to the main board by trying to pry the glued battery off, try this instead. The battery is encased in a plastic wrapper which covers a metalized plastic sleeve. With the battery still glued in position, remove the battery connector from the board and then peel open the black plastic wrap to expose the silver metalized layer beneath. Using a modelling knife, carefully slit open this inner sleeve to expose the battery cells and then lift the cells clear from their wraps. The silver sleeve can also now be lifted free leaving only the black outer wrap stuck to the board. You can now either use or warm hair dryer to soften the adhesive or simply trim the wrap to leave the 'stuck' side in place (it will not interfere with the replacement battery). Far, far easier and safer than the original author's method of battery removal!
The video referred to below shows a battery only 'lightly' stuck to the mainboard - my understanding (and experience) is that this is not usually the case - they are usually VERY FIRMLY glued to the board!