Swaybar bracket help needed - elongate the bolt hole?

Hi everyone. Need to know if it’s possible to oval a bolt hole in a swaybar bracket and if it’s the best solution to my problem. 

Went to install a 1mm larger rear sway bar and found the bracket is also about 1mm larger, so the bolt holes don’t line up exactly with the subframe pockets. Brackets look like this:

I'm thinking to elongate or slightly enlarge one of the holes on the bracket. Only need 1mm or so. Is that my best option and how can I do it?  Put the bracket in a drill press and drill the entire hole slightly larger?  Try to nibble one end only?  Is there another option, since I don’t own a drill press?  I also thought about compressing the bushing slightly but there isn’t enough room for a c-clamp and it would block access for the bolt anyway. 

You'll be fine. I've elongated both holes in the past.

I've done it before as well.  For 1mm I would use a round file (rat-tail) or a grinding burr if you have either, but just drilling the hole larger would work as well.  I would also use a flat washer under the bolt head to support and reinforce the tabs.

Thanks  the suggestions. Found a burr and ovaled the bracket holes slightly. I used the washers as well. Appreciate the suggestions. 

yep, 100% OK as there is very little force being transmitted through those brackets.