2008 Honda Accord rear brake pads

Rotate the caliper piston clockwise into the cylinder, then align the cutout in the piston with the tab on the inner pad by turning the piston back.
Lubricate the boot with rubber grease to avoid twisting the piston boot.
If the piston boot is twisted, back it out so it is positioned properly here is a video to show you

https://youtu.be/j8YwfSKEzZo

Please let us know if you need anything else to get the problem fixed.