I have similar config on my 2011 930D2 Hopper. Front mount deck, PTO shaft supported by two pillow block bearing assemblies. Not sure what keeps shaft in place, but might just be at the very tail end where it terminates in sheave. I looked in my op manual, and I could not see enough detail on drawing to be able to tell for sure. Look at sheave and see if it has set screws. Ought to be one directly over where square key is, and another one 90 degrees around from that. Doesn't seem like that would secure it both directions tho. Better solution might be a shear pin locking front of shaft into front U-joint assembly, locking shaft into the spline. Front U-joint is fastened im smilar fashoin to gear box, which would secure shaft both directions. If neither, may indeed be press fit bearings. Would need to clean shaft ends first, to remove any rust, then use some heat to expand bearing assembly and hammer to drive off .