Load a screw into the strip, positioning it so that it can be screwed into the holes of both the strip and the gutter.

Fold the strip around the gutter, aligning the holes of the strip with the corresponding holes on the gutter.

Screw the screws into the holes of the strip and the gutter, using a screwdriver.

Repeat this process for each strip along the length of the new middle gutter.

Take care not to overtighten the screw, as it may damage the gutter or strip the threads.