If your heart is set on clover - I'd probably hand spray it with round up - then "press in" clover seed.

Side hills are tough though - and clover grows so slow - that if you disturb the soil - you will get annuals that will outcompete the clover unless you mow them a couple times the first year - so if you cannot mow the spots - maybe you should look at other options. I know that the banks of our County roads are seeded with Vetch - I think Hairy Vetch - but I could be wrong. The Vetch really keeps the weeds down - and provides Notrogen to the trees (if inocculated like clover). These banks are rarely mowed - and are allowed to "seed back" most years.