Please choose the correct ending to complete the given sentence: Sports and Fitness: [header] How to change a bmx tire [title] Using a valve stem tool or the tip of a screwdriver let all of the air out of the tube. [title] Undo the wheel nuts or quick releases and remove the wheel. [title] Remove the dust cap (if there is one).

Ending1: [title] Remove the brake pads and lay them out. [title] Unscrew the duct tape that is attaching the tire to the next wheel. Ending2: [title] Dump or fill the tire so the seal pan sits as flat as possible. [step] If there is a smooth side, (a bit bumpy) remove the tray once the sealant is dry. Ending3: [title] Screw on the dipstick to prevent dust and debris from creating any kind of residue. [title] Sterilize an appropriate time and place them in water. Ending4: [title] Put a tyre lever (not screwdriver) between the tire and the rim just far enough to hook the tire. [step] You don't want to contact the tube with the tyre iron because it may puncture the tube.

Answer format: ending1/ending2/ending3/ending4