It should take a 15mm box wrench to do the job.
A wrench
3/8 inch Allen wrench.
15 mm
3/8 inch allen.
disconnect neg. battery cable ,remove pos.cable from starter .10 or 12 mm wrench.remove wire from starter ,no wrench needed,its a male to female connector,remove 2 bolts holding starter to engine,12 or 14 mm wrench,thats it.
get aoil filter wrench and remove and put new one on.
Remove nut holding the trans mount to the crossmember jack trans up off of the crossmember then hand wrench bolts out of trans and reverse process.
Using a suitable 15mm wrench turn the drain plug counterclockwise.
Remove the positive terminal cable from the battery using your pliers or wrench.
The bolts on the starter take a 5/8 inch wrench. The battery cable is a 13mm wrench.
Depends on the year I guess. I have a 2002 Chevy S-10 and I had to remove the exaust pipe from underside of the starter and then just unbolt and remove...not hard once the pipe is off. You will need a socket wrench and a long extention to reach the bolts on the top of the pipe.
The engine oil drain plug is located at the lowest point of the engine oil pan. It should take a 15mm wrench to remove it CCW.