Wireless router turned adapter

Can anyone explain to me how to turn a wireless router into a wireless adapter? I have a spare one lying around and don't feel like buying myself a pcie wireless adapter.

The best way is to install something like DD-WRT on the router but its impossible to say if yours is compatible unless you state what router it needs to connect to as an adapter and what model the router itself is.

I recently unbrickd a old linksys Router and then made it into an adapter by following this video.

Lucky me, I managed to brick mine. The power LED won't turn on, but the ehternet LED is on