2012 Elantra limited rear shock bolt
 

Changing shocks, that inside nut under cover turning, had to cut bolt with wheel. how do I get to that nut, im guessing i have to cut off that cover from the inside, There is about 1.5 inches of bolt left and i cannot get it out. also the bolt is about 7.25 inches long, can i use a grade 5 or grade 8 bolt and just renut it once i get that other piece out ?>?
thanks in advance for any advise or help

There are not sway bars on the rear of this car, just shocks and 2 very large bushings