Thanks Tobias, bit worried about the antenna/coil now, but I never used radio anyway. Needed a metal spatula to scrape out the battery which was pretty well glued in, thankfully it didn’t go up in smoke. Main thing is I got the new battery in and it is holding charge much better than the old one, thanks!
Finally done it but loads more screws needed removing to reconnect the ribbon connectors - these are not slide-on but press-down, so clearance is required. (Had to prise apart and jam open with a blade, bit nerve-racking). Also there were things taped to the old battery that wouldn’t come off; one looks like a supermarket security tag, no idea what it does but it got mangled and so was only partially reinstated
This job is a nightmare and my P9 is very different internally. Also no screws either side of USB on base, so just getting the back off was !&&*. Aborted the mission before I wrecked the %#*@ thing