elecrics

I've messed up, been removing the headlining and disconnected the airbag light in the roof centre console. I should of really disconnected the battery but wasn't thinking at the time, because I turned the ignition on (stupidly to see if any errors happen when everything is disconnected) I am now...

Hi all, I have just brought a T6 panel van and I am going to be slowly converting it over 3/4 years (when I can afford it). Is there specific stages that need to be done before you move on to other stages? Thank you for any help