Advice on changing leisure battery

[smiffy64]

My leisure battery is failing fast and need to replace. I have located it under the drivers seat, so I assume that I need to remove the whole seat to get to it.
The only thing that looks tricky is the wire for the seatbelt monitor/sensor.
Any advice on how to go about doing this job would be greatly appreciated.
Unfortunately, the only experience I have in fixing my motorhome is being ripped off But I am a reasonably competent person so I am willing to try.

For example: Do I need to isolate it at the elektroblock or any where else?

Thanks,
Raymond.

 

[Reallyretired]

Probably sensible to switch off the main 12v switch and as always disconnect the grounded negative terminal first. Sometimes the seat will slide far enough to allow access without removing the seat but depends on whether theirs a swivel

 

[joka250]

If disconnecting the seat belt pre tensioner wiring it's good practice to firstly disconnect the vehicle battery. Ignition off, disconnect battery, let stand for 30 minutes.