I have tried pry bars and a bottle jack but can't get it over the bottom knob.

Are you talking abput part # 15

Yes.

Try using a valve spring compressor , this has work for me in the past,

Thanks. We used a come-along attached to each end and moved the axle with spring into place. I didn't see your attachment until now, but it is similar to the one I had from JD which showed the spring as #16. Thanks again for the info.

Your welcome
Good job.