I have had some interest in how I changed the iron I-beam in the bilge on my 1976 h30. Soo I thought I'd post it for those interested. I changed the design of the compression post to that of the new Hunters. If all you want to do is change the I-beam, I don't think that would be very difficult. You'll have to drop the mast then remove the compression post. The compression post is covered in teak planks that do not have to be removed. The compression post is screwed to the bulkhead behind the head door. Once the post is removed the plywood bilge cover can be removed, exposing the top of the iron I-beam. It will be glassed in on the sides and up the center web. Mine was delaminating off the I-beam. I used a hacksaw to saw thru the fiberglass about 3/4" or so from the side of the bilge. After removing the fiberglass I was able to use a hammer and drive the I-beam back out of the taper shaped wedge it was setting in. I fabricated a 1/4" thick SS plate to the same size as the bottom of the I-beam and drove it back in where the I-beam was. I secured it from sliding aft by a strap bolted to the new plate and over the top of the forward keel bolt. My plate had a pin welded on it to accept a SS compression post, but you could construct a new I-beam by welding flat plates to form a new I-beam.