If you have already downloaded such a file, the general process for handling an ISO repack is as follows:
Repacks are highly compressed; installation can take a long time and may lead to file corruption or missing features (like multiplayer) compared to the official version. How to Install (General Process) raft-v1-09-repack-iso
Follow the installer prompts. Be wary of "additional software" checkboxes that might install unwanted programs. If you have already downloaded such a file,