Replacing inner and outer will be potentially easier than trying to get the crusty, seized outers loose. If you do end up doing just the outers start by removing the jamb nut and soak everything in pb blaster. If (when) that isn't enough, get a torch and heat up the outer rod for a million years then try to loosen the inner. Try to only use an open end wrench too. Only use a pipe wrench as an absolute last resort

OK, need to look at the video again. Thx.