Guessing only and assuming its a small cylinder lock, but most bike keys/locks that I have seen, are usually quite simple, and just about any (even an amateur) locksmith will allow the lock to be opened and the battery removed, making replacement of the barrel simple.
Drilling is an option, but done badly, may damage the part of the battery casing that is needed to hold the (new) lock in place for proper operation.
My having worked as a locksmith after retirement for the best part of a year, I use a Dremel with a special cutter, to cut through the
part of the lock where the tiny moving parts and springs are, thus allowing the lock to be turned with a large flat bladed screwdriver.
Boring out with a drill, just leaves a large hole, that is difficult to "get a grip on" and turn, to release the battery.
This guy shows just how easy such similar locks can be picked, with a relatively tiny bit of (picking) knowledge:-
Here are some pictures from Wiki showing how almost any simple cylinder lock operates:. The 2nd picture shows how the lock is blocked when the wrong key is used.
The third picture show what happens when the right key is inserted:-
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It is IMHO, not as needing "skills" as many people hope for, but which many thieves are not able to achieve!
If you are going to drill, you just need about a high speed drill of around 3mm in diameter, and to drill along the line between the blue and the red tumblers are, releasing them all.
You may need to follow the same hole with a 6mm drill, to get all the "bits" removed.
But remember, I do not recommend drilling!
A locksmith is the better option.
I wish you luck.
Andy
PS. This method below works as long as the right size "Rake" can be found, but I would guess that your cylinder is very small, therefore the right size tool may be difficult to obtain:-