moss problem
 

I've got a problem.I have a 700sq meter garden,that apart from mowing,has had nothing done to it for about 20years.What i've noticed,is that there is very little grass,but an abundance of moss.apart from ripping it all up and relaying new grass,is there a way to remove the moss and coax back,or re-seed grass.

i would appreciate any help
thankyou.

Ive been checking out discussions on this forum,and you all sound soooo in the know,i just cant believe that no-one can help me with any of my questions.
quite amazes me.or is it coz im not a "proper" gardener?sarc.