The remote central locking has stopped operating from they key of my Octy 1.8t. I think the battery has died in the key. I took the key to a key cutter, who said he could supply the battery, but not fit as the key may need to be recoded. Is this correct?

I assumed I could take the key apart, replace the battery, then just carry on using the key.

Its an old style key, not a flip out key

I've replaced a battery, its just a straight replacement and dead easy too

Only replacement keys have to be decoded from what i remember

Easy peasy. This video shows you how: