I haven't found the need to remove my cassette on the road yet......you don't need to remove it to replace a broken spoke.

I would just bring some poly strap if I wanted to remove it.It's only suppose to be held on with 30lbs of torque.

Unlock.....Wrap the poly around the outer gear,tie it to the frame,use pedals to loosen lockring.

Lock.....wrap poly around inner gears,use pedals to tighten lockring.

You can generate 30 ft/lbs with your legs I hope.I know your legs are not strong enough to break the poly strap.