Assuming your AP has an IP of 192.168.1.245/255.255.255.0 then set the IP of your client to 192.168.1.240/255.255.255.0
No DNS or gateway need to be set.
Then open up the web browser on your client and in the address bar type in 192.168.1.245 and press enter, then you should be presented with a login screen.
Provided the password hasn't been changed then leave the user: blank and the password should be admin
Regards
Fred