Remote connect from home to office

My wife would like to access her office computer from home.

At the office, have DSL through Netgear M814 wireless router to two XP computers — hers via Cat5 wire, the other via Netgear USB Wireless adapter.

At home, have cable through Microsoft Broadband Networking Wireless Base Station Model MN-500 to three XP computers — all via Cat5 wire.

Connected today to office router and attempted to change remote management settings to allow range of IPs to access, but after putting in IP and telling router to apply access was lost — received “Page Not Found” message after timeout.

Would like to complete router setup and connection procedures. Need help.

Thanks in advance.