What needs to be fixed?

I assume this is a bead front sight.

The broken stub needs to come out (a few are pressed in, but most are screwed in).

Then a new one can be installed.

Brownells has replacement beads and the tool to install them:

http://www.brownells.com/shotgun-parts/sights/front-sights/index.htm?psize=96

http://www.brownells.com/gunsmith-tools-supplies/shotgun-tools/shotgun-sight-tools/shotgun-sight-installers-prod879.aspx

For what make and model weapon?

The battery's are under the large top cap, use a screw driver or coin to remove. watch for how they come out keeping in mind the positive side up. Hope this helps Fix Ya up.

On the right side of you motor, there will be a sight glass.
You will have to crouch very low, and possibly lay on the ground to see it.
The sight glass is in the right side cover towards the back and at the bottom.

If your oil is in need of changing and has turned dark in color(black). The sight glass isn't so visible when the oil is black.

Thats how you check the oil level with the bike off the kicksatnd and you holding it staight up, while looking at the sight glass.

it would be fear to say its far cheaper to buy a new scope than try to get your old scope fixed,,,there a cheap scope now!

The front sight is fixed. The rear sight is what you adjust. Windage (right/left), and elevation (up/down). Some models may allow the front sight to be removed after the hood is off...

here's a free web sight that has your owner manual for free that should get you in the right direction http://autorepair.about.com/

you can get the service manual you need for your tv at the sight I posted also they give free online tech support and they will help you know if you need to replace any parts and if so that sight has a great parts distributor and can get almost any part you need...at reasonable prices
http://servicemanuals.vstore.ca/