You can view the parts you previously uploaded by simply clicking 'Your Parts + Fitment' from the main menu located at the top of the PC Fitment homepage.
A list will generate displaying all the parts previously submitted. You can remove parts by clicking the box to the left of the part (click 'Check All' if you'd like to remove all parts) and then click 'Delete'. Be sure not to do this unless you are absolutely certain you would like to remove these parts.
If you need to edit a part, simply click 'Edit Part' on the far right column in the line that the part exists and the edit window will appear.
From here you may edit the part number, select a different part type from the drill-down, update the correct ASIN number, change the manufacturer label or edit the part description. When you have made the necessary edits, click 'Update Part'.