Lubricating clutch release bearing guide tube

[Sparkrite]

My clutch action is getting gradually more stiff and as I have isolated the cable as the source, I am thinking it's the clutch release bearing guide tube. I didn't pay enough attention to it last time I was in there but for now I would like to grease it a bit before I eventually have to pull out the gearbox.
Can this be done in situ without any dismantling.