As long as you don’t round off the bolts, just pull till your red in the face and have lost your religion and veins are starting to pop and are starting to growl “you muthafuckaaaaaaaaaa”! Right about that 4th “a” is usually when it’ll give.
Or… If you can get the wrench to hang just right and position yourself just right, you can probably get the bolts to move by putting your foot on the wrench and pushing with your leg and/or kicking it.