Slave cylinder leaking

Hi Joe, I tuck the bell housing and gear box out this weekend to find the whole slave cylinder had burst inside the bell housing and made a right mess inside it. The new one won't be in until tomorrow. I'm getting it from Nissan hoping it would be better quality. When the pedal is hard to push down do you think it is something wrong with the clutch side or the gearbox side? I've never taken any of them apart before, what do you think I don't want to fit the new one and it goes as well?

This is what it looks like but when I fitted that one the bell housing was as clean as if it was new, I hope you can see how much muck that is in there and where it came from it not just oil that is in there it is thick gritty muck. Where do you think it came from?

No, I just woke up having a bad night with my back. It's 3:30 am Sunday night/Monday morning here so the dealer won't be open for about another 6 hours. I've no lift or fancy equipment, so I'm doing it outside. I have to clean it all up and collect the new parts in the morning. It is like dirt mixed with oil but where would the dirt come from the bell housing is pretty well sealed, isn't it?
The last time it went out on me was last July when it went on me it was pretty clean, certainly no muck mixed with the oil, but you'd have a better idea than me. Thanks Joe.

Thanks Joe, but when you said the pressure plate, do you mean I should take out the clutch and replace the pressure plate as well?

Should there be play like in the short video I have attached or is something like the clutch plate worn-out?
I haven't put in the new slave cylinder yet. When I saw the movement where the fingers are in the outer plate is, I said I'd ask your advice first. Thanks Joe.

Okay, I didn't know if it should have any play or not, but you don't think that a small bit of play was the cause of the slave cylinder getting worn out in a few months? And what do you think can be causing the heavy clutch pedal?

Thanks Joe, I'll order a clutch and pressure plate tomorrow and I'll have Wednesday and hopefully it won't be as heavy if it doesn't make it any later, at least we can say we tried, thanks.
Is there much of a time difference between here and where you live? It is 9:40 pm here now.

Hi Joe, Happy St Patrick's Day.
Sorry I haven't got back to you before now.
I was doing the car in my back yard, and we had a week of terrible rain and my brother lives in another country and he gave me a lift with the bell housing, and he was working and was only off on the weekend. So got the job done finally just brought it for a test drive today and it is running well and you were right about the heavy clutch it was the pressure plate it is much lighter now and running better than ever thanks for all your help and advice I really appreciate it hope all is well with you take care.
From Tony