power steering fluid and flush on mercedes benz 300 d turbo diesel
 

I want to do a ps steering fluid and flush on my 84 300d diesel turbo I was wondering if anyone can give me some insight on doing this. I read and seen the diy but Im not exactally sure which hose is the return hose. If anyone can help that would appreciated. and also do you have to put any adhesive on the gasket on the cover of the reservoir? im new at this. thanks.