or you could select level change on MCP
The above statement does not delete the reduced thrust, it will continue to use CLM-1 or CLM-2 if used for takeoff.
TOGA will remove the reduced thrust selection (as a 2nd TOGA press gives FULL thrust) but can only be done at low altitude as stated.
Once above that altitude, N1 page selection is the only option or wait until the aircraft is climbing higher and it automatically changes.