Hi all, due to lock down my battery is completely dead.Going to be putting a new one on in a couple of days. Is it just simple swap or any circuit issues issues I should know about.

The battery swap should be okay to retain settings but if in doubt you can use another battery to connect via wires to put a charge through the leads whilst disconnected.
There is a special tool for this but you can use wires for cheaper option

https://www.ebay.co.uk/itm/Draper-12V-Car-Vehicle-Radio-Code-Clock-Memory-Saver-12V-Socket-Battery-Changing/133344192488?hash=item1f0beee7e8:g:3hMAAOSwOGleVSSs

Thanks a lot. .just changed it,feel like I got away with it.

Good to hear and thanks for letting us know the outcome

Thanks..update,I did have code 59 which is "open and close drivers window and had to reset the idle,simple hold revs at 2500 three times.

That's not too bad then and hope the battery has improved things