Hi Marv, yeah I'm not quite sure if you're talking about tapering the whole existing object by squishing it's end down? If so then that's not generally how you'd do it, you want to build it tapered from the start instead of trying to squish it to be tapered later on. Or do you want a new tapered section at the end like Brian shows above?
At any rate, in v3 there is a new tapered extrusion function that can help to build tapered objects, it's available under the Extrude command here:
Or, since you know the start and end sizes of your profiles, you could create two sketches and loft between the two.
In your loft sketches though you would need to leave the recessed channel in the bottom of your part a uniform size between the loft curves since it looks to be some sort of alignment feature, but for the main body area - tapered extrusion or build it from two loft sketch curves would be my approach. Might need guide curves if the geometry moves around in someway that you don't like.
