What tool will remove the bolts holding in the wiper motor on a 2006 Crown Victoria?

Particularly the two bolts closest to the windshield. And most particularly, the one on the drivers side.

I tried with a regular 3/4 ratchet, including using a swivel, but I couldn't get it in there. I tried with a ratcheting open end wrench, but that kept slipping off. I didn't have a regular open end wrench with me at the time.

 

There are times when a metric "fits all" also known as an "adjustable wrench", comes in handy.