How to remove - replace security locks - Not Locked, No Key

[Colink2]

I have purchased a van with security locks. The locks are unlocked but came with no key. Same as this lock https://www.vantagevcltd.co.uk/wp-content/uploads/2016/02/33.jpg

I assumed that I would drill the rivets on the outside, remove the cylinder and fit new cylinders.

The manufacturer tells me I need to get a locksmith to do the work otherwise I may damage th evan. (They know they are unlocked).

Any comments / advice?

[bortaf]

For a start i'd have asked exactly why a non locksmith removing them would damage the van seems a very vauge sweeping statment to me, a sort of covering thier arses cos they don't know the answer kind of statment ???
you may need to turn the lock to aline the latch with hole to remove it, like euro house door locks ???

[Altransit]

you may need to turn the lock to aline the latch with hole to remove it, like euro house door locks ???

Isn't that why you need to key to remove the lock? It's a while since I did mine, but I seem to remember having to turn the key partially to line up two tabs so it can be extracted. Otherwise the lock needs to be drilled out from the barrel