I am new to this, so i havent tried anything other than minor maintenace.

I have a Specialized sectuer with what appears to be threadless stem. It looks like all the risers are already below, so i am assuming i will have to buy some more.

Can a average handyman with limited bike knowledge do this on his on, or do i need to take it to a shop? If i need to take it toba shop, any ideas on how much i might be looking at?