Changing bits in a table-mounted router can be awkward, unless you have a router lift that raises the collet above the table. If you’re not lucky enough to have one of those lifts, you can try to work underneath the table, or you can remove the router from the table every time you want to change bits. Or you could just get a bent or offset router wrench — it allows you to access the collet without removing your router from the table.
I found two different sources for offset wrenches: Woodpeckers and Sommerfeld. CMT also sells bent wrenches, but most likely they’re Sommerfeld’s wrenches — he’s collaborated with CMT for some of their routing systems, and the wrenches look suspiciously alike.
You can find offset or bent wrenches for most router models. Look to pay from $15 to $20 for each wrench. Some routers, like Porter-Cable’s, require two wrenches to change bits — unfortunately, owners of these routers will pay double.