It's a minor surgery, and you can also donate without surgery via apheresis. In the case of surgery you're put under and they dig around in your hip bones. You

It's a minor surgery, and you can also donate without surgery via apheresis. In the case of surgery you're put under and they dig around in your hip bones. You feel sore for a couple of days and then continue life as normal. It's safe aside from the normal risks that comes with any surgery. Source: I donated bone marrow