This is the only way to do this job.  If the bolts are too tight for a
bar that will fit under there, go rent a 3/4" electric impact wrench
with the proper socket.  It'll be the best $25 or so dollars you've ever
spent on a repair.  Be sure to use a torque wrench to tighten them back
up though.
--
Stuart MacMillan
Seattle

'84 Vanagon Westfalia w/2.1
'65 MGB (Daily driver since 1969)
'74 MGB GT (Restoring sloooowly)

Assisting on Restoration (and spending OPM):
'72 MGB GT (Daughter's)
'64 MGB (Son's)

Stripped and gone but their parts live on:
'68 MGB, '73 MGB, '67 MGB GT