A lot of play in clutch pedal - hard to get in gear

This happened pretty fast, over the course of 2 days of driving. The pedal is getting more and more play and harder to get in gear.

From what I have read, it is most likely the clutch cylinder? Are there any guides on here for changing that out.

Any other things I should be checking?

I've resolved this issue.

My brake fluid reservoir was low and after filling it up I didn't notice a difference, but after giving it more time to build up pressure it is now working.

You can delete this thread if you want.

...but why was the fluid low? Brake fluid does not evaporate.

Check for signs of leakage on your master and slave cylinder first.

Brake fluid? I'm having a similar issue with my 86 2WD when shifting. Especially 1st and it grinds going into second. It seems like the clutch isn't fully disengaging even when the clutch pedal is pressed down all the way. How did brake fluid solve this?

So.... The fluid reservoir that contains the brake fluid is shared by both the brake and the clutch systems.
As brake friction material wears away, the pistons move further out and the system volume increases.

That said, if the fluid has dropped sufficiently to cause a problem with clutch function, I would be take the time to look for leaks.
Leaks can develop anywhere, but are harder to notice when they occur in hidden areas.
While it is "common" to have a leak at either the master or the slave, it can occur anywhere, lines can rust, junctions can fail, so trace the lines from Master to Slave and all points in-between and check both systems as a leak in one WILL affect the other.

The other point to make about brake fluid, it is designed to absorb water and must be flushed regularly (every 2-3 yrs)
Brake fluid should be clear, as it absorbs more moisture its colour will darken, it should be changed when it approaches the colour of honey.
At some point it won't be able to absorb any more water and it will fall out of suspension, causing all sorts of corrosion inside the system and is the number one cause of component failure (read that as callipers and wheel cylinders and master/slaves).
BB