See this image?


There are three flat bladed screws on top of the FD. You remove them
There is a very thin O ring underneath the FD. be careful of it.
Get a new one from your local dealership - it's a very cheap cost.
Be very careful when you install the new O ring.

The EHA is mounted on the side. There are two small green rubber O rings between the EHA and FD body. Get new O rings from the dealership as well.

You will need to have the air mixture ratio adjusted after you fit the new FD. Technically the FD plunger to AFM should be adjusted properly as well.

This image was used for some other explanation. The "here it is" refers to the filter between the incoming fuel line and the FD.