E/EE bond redemption by non-owner

I have a few mature bonds from childhood that have been sitting in a safe deposit box under my parents’ control. I’m now an adult and currently live on the opposite coast.

Obviously I could have the bonds sent to me and cash them in in-person, but since I only have a Schwab account (no local bank), I would then need to turn that cash into a form that I could deposit electronically. Logistically it seems it would be easier to authorize my parents to redeem the bonds on my behalf and transfer the equivalent value to me.

I know there are processes for giving authority to a third party (in this case, my parents) to redeem a bond on my behalf, but am unsure of which exactly it is and how time-consuming it is to do in this way.

Is the correct way to go about this to grant attorney-in-fact status to my parents? Is it relatively simple to do or would it still be easier to have them mailed and go through redeeming/converting them myself?