I have a 1995 chevy lumina, it will not urn over,

Charge battery , clean cables at battery and starter.

Undo your terminals... Get a battery cleaner (fine scrapper) and clean(scrap) your battery post AND terminals.

i think you need a new starter. my suburban cranked really slowly as well, a new starter fixed that problem

these are located at the front of the motor were the motor bolts to the transmission between the rad and the motor

check the wires on the starter,,the one going to the battery

Bad solenoid

sounds like you have a lame solenoid on the starter .i'd start there.get a voltage tester and test for 12 volts at the solenoid terminal if there is 12 volts and the starter still doest engage when you hit the key test the ignition wire on the solenoid when you turn the key it should apply 12 volts as well .if works then take the starter out and find a good repair shop and try a new solenoid first then the starter is next to test .

Not that bad, jack up front of car used jack stands, starter sit between radiator and engine, on engine block above oil pan, disconnect battery 1st.

most cars have a switch on the clutch or automatic transmission that will not allow car to start unless switch is closed your uncle bypassed that switch when he jumped it at the solinoid there is a possibility that the switch for the starter
at the column is bad but not as common as the other switch

starter problems