I trimmed down the cone a bit. but the trick is to get some long nose pliers on the other end of the rubber and having copiously lubricated the cone end pull it through. This method stretches the rubber and hence thins it.
I've done two Ten sidestands.
...................and then the trick with the springs is to use some 6mm rope and using it like a pulley from the spring onto the sidestandcross bar you will easily be able to get the spring onto its location.
I've done two sidestands now and my bike is in for a service. For some reason the mechanic has taken the sidestand springs off!
I have told him I will show him how to get them on quickly and safely.