Musicians Roadhouse

Hi Guys, first post here so if anybody would like a beer I'm at the bar! ....picked up a Class 5 Head yesterday and the little amp has completely floored me.
I plugged it into my Vox Heritage open back cab which has a Celestion blue in it....the results were fabulous! Gorgeous THICK singing lead tones with my CMAT Signa Drive pedal with both my strat and les paul
So I want to spend some time today experimenting with tube swaps....I have some old Mullard's and various other EL84's and lots of 12ax7 to try in the amp so want to pull the chassis. I am hoping someone will kindly chime in and explain the correct procedure for removing the chassis from the head. I have just spent a fruitless hour with the search function looking for this info but have now given up! :)

Just remove the four screws from the back the 4 from the bottom bottom and she will slide out, you don't have remove it to change the tubes the are right at the rear so just take off the back cover. There have been problem with the military spec'd el84, you can search the forums, I like the JJ EL844

Thanks duke, yea I tried to remove the back panel yesterday but it was very reluctant to come off....it does seem quite flimsy, so didn't want to force it too much. Decided the safest route was to just put the screws back in and check in here and ask.
Interestingly my Head is one of the final batch of twenty that marshall made. The original owner who I just bought it from lives just a few miles from the Marshall factory.....marshall put non standard tubes in at some extra cost to voice it to his needs, so I am interested to see what they put in there?