I think he meant the can opener itself doesn't weight much, but that point is kind of moot.
Go to that small swiss army knife and use the opener included with most of them if it is an absolute must.
Pack and Sleeping bag are usually major offenders, and seems to be true in this case. Both together probably shouldn't weight what either do presently and that is pounds not ounces or grams.
Certainly reduce redundant clothing. Alcohol Stove and something like a Heini pot cook kit.
Change out the overweight stakes. I have a set that weights pounds and another that is nothing in comparison. Pounds for Ounces exhange there too!