It is possible to have your HELM fork converted from Air to Coil as part of a 100 hour service at an authorized service center or through direct factory service. If a 100 hour service is not needed (e.g, on a brand new fork) then a suspension capable shop can also handle this conversion.

This is a one way street: once set up as a Coil fork, you can no longer run it as an Air fork due to internal scoring on the stanchion that can be caused by the spring. As such, Coil to Air is not option.