1. Restore the datafiles.
2. Startup Mount.
3. Recover database untill cancel.
4. It will ask you for the archived redo log files.
5. Enter the location of the archived redo files.
6. the entries from the online redo log files will be applied too if available.
7. If its complete recovery you can open your database, otherwise in case of incomplete recovery you will have to use resetlogs option.

(I assume that you have a copy of current control file)

Sanjay