1. Get oil can.
2. Remove oiler from rifle sling assembly.
3. Unscrew cap on oiler.
4. Pickup oil can in right hand while holding the oiler in left with the opening from removed cap up.
5. Slowly add oil until the oiler will take no more.
6. While holding oiler in left hand in a manner to prevent spilling the contents, set oil can down.
7. Pick up oiler cap with right hand and screw it as tight as possible.
8. Wipe all excess oil from oiler.
9. Reverse the removal procedure and install back on the sling assembly of gun.
Now you can rush out and tell everyone, "I have oil in my oiler." Seriously, why do you want to refill the oiler, most of them leak, and you will find at some point that you have oil all over the sling and stock. Just hope that it is not on the wife's new sofa wwhen it happens.