Franky,
It's pretty easy, really. The car doen't have to be all that level. Just take out the bottom plug and let it drain out. I usually let it drain for a few hours to get all the old stuff out, then, put the drain plug back in. Unscrew the filler plug (on the passenger side) and fill it with 2.75 quarts of fresh fluid. I use a cheap plastic pump from an auto parts store that screws into the quart bottles. You pump it up and into the transmission through a clear plastic tube. Keep going until it starts coming out of the filler hole. Then replace the filler plug. It's a good workout for the hands and forearms.
One tip, I like to epoxy a small magnet to the drain plug to collect any metal bits that wear off the gears.
To answer your other questions:
"I have never changed transmission fluid in a manual transmission. Curious if anyone is using the Ultimate Tremec Transmission Treatment fluid from Performance Unlimited."
No. I have used standard ATF and Red Line fluid. The standard ATF shifted better. Next time, I will use the GM Sychromesh fluid recommended by Hal Copple.
"I am curious as to a few things, is there a filter"
No filter.
"Does the car need to be level?"
It should be relatively level.
"In gear?"
Doesn't matter.
"What weight manual (gear?)
oil should be used for spirited street use and occasional track course time?"
Manual gear
oil is 75/85 weight. Tremecs use much lighter automatic transmission fluid.
"How much of the Ultimate Tremec Transmission Treatment is mixed in or do you not need it?"
I don't know, haven't used it. Don't like "Snake
oil".
How often should it be changed?"
Every 15,000 miles.
"Is there an additive that adds to the life of the transmision?"
There are lots of high-priced gimmick lubricants. Stay far away from them. They will cause you grief.
"Many thanks for anyone willing to share their suggestions."
You're welcome!
Paul