The first time I fitted my M+ tyres was to a set of H Plus Son Archetype rims. I don,t know whether it was the fact the tyres were new, or the rim depth, but I found that by following the video linked to by SuperSuperLeeds (can't believe I just typed that) l managed to get them on without levers.
I've just moved them onto the wheels that came with my new CAADX and although I needed to use levers to get them off the Archetype rims, they went onto the Maddux rims by hand very easily. Maybe they were a bit more supple after about 2000 mile useage?
Today I'm fitting a set of SKS Mudguards to the CAADX and just know I'm going to have a nightmare with getting the stays to fit around the rear disc brake calliper. Still, slow and careful should do it.
Graham