Brake fluid reservoir fitting issues

My brake reservoir was leaking a little so I've got two new rubber bungs.

I've checked the reservoir outlets for any cracks in the plastic and seem ok.

Question is how on earth does one fit  the reservoir - rubbers grommets fitted to the the master cylinder first or or fit them to the resevoir first ?? 

I fitted the grommets to the master cylinder first then put some grease on the reservoir outlets then pushed it on.
My grommets where the original ones when I changed the master cylinder so go carefully when fitted the reservoir.