yup about collar. here is a tip though - for a newbie- it will bee best if you shift the pto selector to rear pto only, this will allow you to rotate the shaft to a better gripping position. I did that for awhile and now gotten used to it and now I can just blindly reach in, grab collar and go by feel which way to twist shaft to disconnect in less then 1-5 seconds.
just practice and you will bee an expert in no time at all.