Here is a general outline of the steps involved in replacing the rear main seal on a Ford:
1. Disconnect the battery.
2. Remove the transmission fluid pan.
3. Remove the driveshaft.
4. Remove the transmission mount bolts.
5. Remove the transmission crossmember.
6. Disconnect the transmission linkage.
7. Remove the speedometer cable.
8. Remove the starter motor.
9. Remove the transmission bolts and remove the transmission from the vehicle.
10. Remove the old rear main seal from the engine block.
11. Install the new rear main seal into the engine block.
12. Reinstall the transmission in the vehicle.
13. Reattach all removed components.
14. Fill the transmission with fluid.
15. Reconnect the battery.
It's important to note that this is a general guide and the exact steps may vary depending on the specific Ford model and year. It is recommended to refer to the service manual for your vehicle for specific instructions.