hi m8 i am bodywork specialist

there are a random amount of ways 2 do it,all down 2 the way u want 2 do it really

u could drill a hole for the rivits(make sure they sit low down) make sure it is pressed down securely,then get some 'stickerflex' i.e:sealer and run the gun along,then run your finger across it so it is even all the way along,leave it 2 dry overnite,now there will be a gap above the rivet(in the hole u drilled)now skim that over with bodge/bodyfiller smooth it all down and bobs ya uncle

or

make some key marks and fibreglass it in, then skim over the fibreglass with bodge,smooth it all down so it is all even and hey presto

hope u get sorted m8,anymore questions then feel free 2 PM me