What are the steps to rough in plumbing in basement after the concrete is busted up?.?

I would recommend you call a professional, as plumbing mistakes in this job could be costly. That is not 3.5" pipe. The size is based on the ID.

1. You need a vent for each fixture. The sink vent could be combined with the toilet vent. The toilet vent should be 2"-3" (depending on the local codes). Normally you would have used 2x6's in the wall behind the toilet for a 3" vent line since the fittings wont fit in a 2x4 wall.

2. You cannot use a 3" sanitary Tee horizontally where you tie into the existing line, it should be a 3" Wye. If you have enough depth, you could use a tee and a 1/4 bend, but you don't have enough depth below the floor.

3. The hole over the existing line should be about 36" in diameter to access the line.

4. If you tie the vent line into the toilet drain, you must go into the top half of the pipe. Vents must never enter the side of a horizontal drain.

5. The slope should be 1/8" minimum to 1/4" maximum per foot on the lines.

6. The lavatory drain could use a 3x2 wye, not a tee, to tie into the new 3" line to the toilet. The 2" side should be rolled up vertical into a 1/4 bend. Then the 2" pipe would use a 1/4 bend to enter the wall. The vertical 2" wet vent could serve as the toilet vent also, if local codes allow. You would use a 2 x 1.5" sanitary tee to tie in the lavatory drain into the 2" wet vent in the wall.

Some locals will not allow wet venting a toilet. You should check with your plumbing inspectors before you proceed.

Rough In Basement Plumbing

Thank you very much for your informative answer! I'm actually working on the vent pipe now and going back and forth with pictures of my work to a licensed plumber in my area to ensure everything's up to code. I thought this would be a much simpler project, lol.