As said, the keel doesn't have to be right down, just far enough to see the patch covering the bolt holding the ram. You're fortunate to have a cradle; I had to coincide my work on the keel with the availability of a travel hoist - lift me up to take out the keel bolt, put me down (on the keel later), replace the ram, lift me up again until I can see the bolt hole, leave me hanging while I put the bold back - no time pressure then!
The article on removing the ram is excellent - especially making sure all the pins and split pins are tied on, and all tools (spanners, screwdrivers, etc) are tied on too!
An additional tool I found useful was the bent wire coat hanger - see later ...
A couple of thoughts.
https://www.silmid.com/l...t-225gm-was-dtd900-6065/ but I have to admit that the old bolt came unscrewed (relatively) easily.
http://www.denso.net/densotape/index.htm extensively.
3) As said earlier, wire brush the ram casing to remove old rust (take care round the stainless steel piston, then apply several coats of Hammerite. My ram supplier recommended Denso products, apparently the Isle of Wight ferries use them extensively on their hydraulics, so I smeared Denso grease over the ram, then wound round Denso tape, but not over over the anode. At some stage, someone had wound Denso tape around the anode, which was in excellent condition, but it probably doesn't help it do its function.
4) Fitting the ram back, I lowered it back on a halyard, but first had to use the bent coat hanger to scrape out lumps of rust from the old ram and dried mud from many years of silt before the bottom eye would relocate. Then the copper guard, the Denso mastic, followed by a skim of Isopon.
Good luck!