Do it now. Those who do not procrastinate get more done with less stress and more satisfaction. Don’t put off dealing with procrastination! Having a project hang over your head for extended periods of time can be painful.
Usually there is one small (or large) piece to any project that we would love to avoid having to do. It is a bottleneck, but it will have to be faced and done sooner or later. Avoid the mental fatigue and get to it. Get it done and behind you. You will gain the satisfaction of completion and the rest of the project should progress more smoothly.