I have done this at least ten times, and always seem to have more issues with the front bolt spinning/breaking free in the rubber bushing than the rear shackle bolt. Heat and lot of penetrating oil sometimes works, but I have honed my skills at the reciprocating saw in this location.
After it’s been replaced (and that front rubber bushing resleeved with a steel insert) once, it will be easy to change in the future.
Erick Riggs