i will try a small pair of good vice grips before i drill,
and i just took 2 apart recently and had to do it.
that hand impact tool is priceless.
ive had mine like 25 years, think i paid like 2$ for it at a flea market
take a loook at this link, i got a stainless allen set here, 18$, came quick,
they were polished real nice, were in seperate bags marked for where they go,
and had 1 extra of each bolt.