If the iR2520 is networked then you will need to determine what IPv4 address the printer is using so that you can connect to it from the Mac. If you need assistance with how to find the IP address then please reply.
Once you have the IPv4 address you can then download and install the Canon UFR2 v10.8.1 printer driver. With this driver installed, open Printers & Scanners and click the plus button to add a printer. Then select the IP icon and enter the IPv4 address of the iR2520. Then set the Protocol to HP Jetdirect-Socket and leave the Queue name blank. Change the Name from the IP address to Canon iR2520 and then in the Use menu, click on Select Software and then browse for Canon iR2520. Select it, click OK and then click Add to complete the printer creation. Now see if you can print.