Battery replacement is in the owners manual. From what I remember it's not a very hard thing to do- I didn't replace mine, but I disconnected it while I was wiring my amp and subs in, so basically the same steps. My carpet was already cut, so it wasn't a big deal at all, but assuming you have the stock battery I would have to say the hardest part is cutting the carpet and getting to it- not hard at all.

 

can anyone tell me where and how many batteries there are on a gl450 2007 and where they are located

 

Hello. There are two. Underneath the passenger seat. You have to move the seat forward until it can't anymore, move the backrest forward. Open the rear right door and look underneath. You have a plastic part along with a another one. Remove those and your both batteries will be there. Main and Aux battery. Your main is an AGM battery and the aux is a rechargeable 12v. Space is limited so do your best. First, remove the main battery. Then your aux. You will have to finesse it a bit, but patience and beer is a way to go. GL.

 

" You have to move the seat forward until it can't anymore, move the backrest forward and move the seat as high as it will go.

 

I did both batteries recently, and the description above is spot on. I did not have to put in any stereo codes, etc. after the replacement. As I recall, the aux battery is tucked under some metal, to the right of the main battery and may not even be visible without removing the main battery.

good luck!