I want to replace a broken front spring. I have done this before on my son's Multipla. I have already removed the two big bolts off the strut leaving one as support. I have loosened two of the three top bolts using a 12-point 13mm socket and t-bar. I cant get this on the rear bolt. Anyone remember what will fit as my 13mm ring spanners are too short and slip

Aha. I remembered there is just enough room for socket and torque wrench which gives enough length to get started. Then remove the socket and use a ring spanner. Or use a breaker bar