Our friends at This Old House have a great post on how to quickly patch a cement floor. They basically suggest four steps. We will summarize them here, but we suggest reading the full article for more detail.
- Level and undercut the bottom of the hole
- Brush on bonding liquid
- Add concrete to the hole
- level
Keep in mind, this sounds simple but it does require some skill. Many manufacturers also make vinyl and epoxy compounds that will do the same thing.