The M60 crossovers are attached directly to the back of the speaker binding posts. There are two pcb boards, one on top of the other, and the two boards are connected together by a pair a red & black wire. You get at the crossovers by removing the black binding post basket on the rear of the speakers.

The bottom pc board which is connected to the lower set of binding posts has the crossovers for the woofers and also the crossovers for the tweeters. However, the tweeter section is actually fed (black & red connection wires) from the upper pc board which houses the mid crossover and is connected to the upper binding posts.

So the tweeters & mids are connected to the upper set of binding posts and the woofers to the lower set of posts. Again the tweeter cossover section actually sits on the lower pc board.

The hardest part in doing this was to follow the pc board tracings and get the crossover laid out correctly.