Set a ladder reaching up to the gutter. Be doubly sure that the ladder is secure. Consider using a partner to hold the base of the ladder.
Use gloves or a trowel to clear the debris from the gutter and drop it to the ground or place it in a bucket. If you do drop the debris to the ground, try placing a wheelbarrow below so you don’t have to clean up the ground, too.
It is very difficult to get all the little bits of debris out of the gutter with gloves or a trowel. After doing the majority of the cleaning, use a garden hose to flush the remaining bits away.
After finishing up, check for spots where landscape has eroded or water is pooling. If the the gutters are clean and this still occurs, there might be gap in the drainage or splashing from a high segment.