About to change the front pads alone on my 300SD. They are worn down to about 1/8" thickness and the indicator started coming on like it should

Rotors/bearings are still in good shape and I just planned on changing pads with a new set of PBR's I bought of Roy/Phil.
Do I need to remove the calipers or is it normal to just slip new pads in place once the pins are hammered out?
I understand that I'd still have to press the pistons back in (crowbar against rotor?) and removing it completely wouldn't be that big of a deal if I had to with a C-Clamp but I just wanted to know if that's expected/normal/ridiculous or if there is a shortcut. If it is to be done that way, is it hard to compress the flat spring behind the pins?
I searched around for the answer to this question but couldn't find exactly that.