Hello,
The worst part of the job is removing the large mounting plate underneath the transmission. Some of the many 17mm bolts are above the exaust. An exhaust heat shield can get in the way also. You may need to removle all the exhaust hangars and allow the exhaust to move down giving you a bit more room to work on the bolts.
After the cover plate is off, just follow the metal vacuum line from the engine down to the modulator. Do not disturbe the little square adjusting bolt and lock nut. You will see three 7mm or 8mm bolts which fasten the modulator housing to the transmission. Once the three bolts are removed, the diaphram is easily replaced. A bit of fluid may escape, but you do not have to drain the fluid. Be careful not to loose the spring when the cover is open up . The diaphram installs easily. Most likely, no modulator adjustments will be needed.
Keep us up to date.
Joe Alexander
Blacklick, Ohio