The new bushing goes in the same way the old bushing came out. The MIS tool is always "pulling" the bushing towards the tool.
To remove the bushing use the smaller round block so the bushing can be pulled out, with the smaller round block passing through where the bushing was installed.
To install the bushing use the larger square block so the bushing can be pulled in, with the larger square block eventually hitting the RTA indicating the bushing is pulled into the correct position.
The new design of the RTABs means you can install them in either direction, whichever is easiest for you to use the MIS tool.