As others have said, the "half spade" into the terminal wil work but not very well. It really is a "kludgy" way of doing it.
If you do not want to modify the cables, I like the option suggested by Hifihvn best. The problem is that the spring contact counts on the deformation of the wire to create a good contact surface. The solid pin will not deform and you are left with a very small point of contact. It is better than sticking the spade in there, but not by much.
Really, the best connector is no connector. Cut off the spade and stick the wire into the terminal. That connection will be electrically and mechanically secure.
hth