Herjólfur sails from Westman islands to Landeyjahöfn which is located on the south of Iceland. You can both drive to Landeyjahöfn by a regular car (no 4×4 car is needed) or you can take the bus, if you are travelling from Reykjavik, you could go from the Mjódd bus terminal to Landeyjahöfn
If you have a car you can take it with you over to Westman Islands.
The ferry ride takes 35.minutes.