Finding right place to drill a cartridge may take some trial and error. If you proceed logically you should get it first time. For instance if a cartridge has two chambers, one with a sponge and one without, drill in reservoir side, not sponge side. In a multi-chamber cartridge with several colors drill over place where you suspect first color is and use a toothpick to sample color. The chambers will usually have some kind of dimple or air hole directly over each chamber.

Start by injecting a small amount as a test, like 2cc or 3cc for color cartridges and 8cc - 10cc for black cartridges. You can add more if test is successful. Try to avoid overfilling cartridge to avoid cross chamber contamination.

Take notes in case you kill cartridge somehow. Your next attempt won't be possible until you buy another set of cartridges and use them up. If you're like me I won't remember what I did in a few weeks. (or days for that matter, that's scary!)

Use static tape on print heads. It has no adhesive and it needs to be applied properly. Many people do not know how to properly apply static print head sealing tape. The trick is to heat up print head before applying tape. Get yourself a hair dryer and heat up print head. Then take a strip of static tape and position it properly and while print head is warm simply dab your finger on tape over print head. The slight pressure will bond tape to print head and hold it in place. The heat temporarily expands tape so when it cools off it will shrink slightly and form a bond around print head. Add a cartridge clip and you have best known method for storing cartridges with print heads.

A note of caution here. Some of you will be tempted to use a heat gun. A Heat gun can throw off an amazing amount of heat, probably enough to destroy print head. If you don't have experience using a heat gun in this fashion please use a hair dryer.

Even if you don't refill a lot you might want to keep a roll of print head tape on hand. Sealing a color cartridge improperly can cause cross chamber migration of ink and that is a contamination that you definitely do not want to deal with.