whoa ... noo ... don't be cutting those wires, those are not
shims, those are the transducers for your pickup system.
Shims are sometimes under the saddles but they are made from rosewood and easily removed.
I reckon you don't have shims, they've been removed when the pickup was fitted.
To lower the action you will have to have the saddle height reduced instead.
Put it all back together and step away from the guitar !