Broken brake bleeder valve

I was doing a brake job on my 1991 Toyota Camry and got careless and accidentaly broke off the brake bleeder valve on my front disk caliper. It is broken flush with the caliper. No fluid comes out at all so I am not worried about a leak.

What is the best way to fix this? I don't want to leave it open so that water can get in there and start corroding through.

I thought of driling and tapping it out, but am worried about contaminating the fluid in there or not getting a snug fit.

Replacing the entire caliper is not in the budget now (why I was doing this myself in the first place).

If anyone has a quick answer, I'd love to hear it.

Thanks