Tree felling using a chainsaw can be dangerous if proper safety precautions and techniques are not followed. Here are some general steps to follow when felling a tree with a chainsaw:

1. Plan your approach: Before starting, you should identify a clear path for the tree to fall, making sure that there are no obstacles in its way. You should also make sure you have enough room to safely work around the tree.

2. Assess the tree: Determine which direction the tree is leaning and which way it is likely to fall. You should also check for any signs of rot or damage that could affect the tree's stability.

3. Create an escape route: Identify a clear escape path that you can use to quickly move away from the tree in case it falls in an unexpected direction.

4. Make the notch cut: Starting on the side of the tree where you want it to fall, make a horizontal cut into the trunk at a height that is about one-fifth of the tree's diameter. This cut should go about one-third of the way through the tree.

5. Make the felling cut: Move to the opposite side of the tree and make a straight cut through the trunk, slightly above the notch cut. This cut should go all the way through the tree, causing it to fall in the desired direction.

6. Move away from the falling tree: As soon as the tree begins to fall, move quickly along your escape route to a safe distance.

7. Cut the tree into smaller sections: Once the tree has fallen, use your chainsaw to cut it into smaller sections that can be more easily handled and removed.

Remember to always wear appropriate personal protective equipment, including eye and ear protection, a hard hat, gloves, and chainsaw chaps or pants. If you are unsure about your ability to fell a tree safely, it's best to hire a professional arborist.