Here's what I might do.

1. From left to right you have switch 1, 2, and 3. You are replacing switch 1 with dimmer 1.
2. Correctly tag switch 1's black "hot" and "light" wires. Disconnect all wires from switch 1.
3. Loosen the screws of switch 2 and switch 3 that attach them to the electrical box.
4. To switch 3 attach (a) the ground wire and (b) the ground jumper that connects to switch 2.
5. From switch 2, disconnect and discard the ground jumper that connected to switch 1.
6. To switch 2 attach (a) the dimmer 1's ground wire and (b) the ground jumper that connects to switch 3.
7. Connect the remaining wires to dimmer 1. Turn on the power and test.
8. Attach dimmer 1, switch 2, and switch 3 to the electrical box.

Remove the ground wire from the existing switch, straighten it, and connect it to the ground wire from the new switch with a wire nut. You don’t have to cut the existing ground wire.

hi bob - thank you for your reply - the ground

wire attached to the existing switch is a loop because it connects to the other switch presently. i've included a mock up to show what i mean. so do you mean straigten the loop so its a tighter loop? i tried but its hard to fit it all into the nut, but i could try perhaps a larger nut - but i just wated to make sure i understood what you meant by straigthen it. thank you again.