That depends on what little 25 HP you have. That's why the moderators always ask for the model number.
The shift linkage is behind an oval plate on the midsection of older modles (thru 84) the plate has two flat screws. After the plate is removed you'll see a brass connector with two screws. Remove the bottom screw.
On newer models (85 & UP) the plastic water pump screens have to be removed, a coupling undone and the plastic keeper and upper nut removed from the shift rod.
Make sure you don't miss the water tube when reinstalling.