bathroom faucet handle fell off

I am stumped... our bathroom faucet handle fell off and I cannot figure out how to reattach it. When I look down though the little hole I can see the screw sitting down there. I do not want to break the plastic but I cannot see how to get in there. It does not appear like removing the faucet will help it all. It seems to me one has to go in from the "top-side".. but how? I have posted a pic and also a pic of the back side of the stem so someone might recognize this logo so I can figure out the brand.

Thank you for considering this everyone!!
Dan

Some trim screws on to the valve body up top. Try twisting the remaining chrome part counter clockwise. You shouldn't have to twist that hard if it is this type.

from the look of this picture it looks like it just pops right back on. All the threads seem to still be in tact. Just make sure and support the underside while you are trying to reattach. Also try removing the other side and see how it is attached and replicate the exact same thing on the left side.