Well, its a hand held. Not really known for the best range. But in order to make it get out better the only thing you can really do is peak and tune it. That will make the radio put out more power.
I have never worked on this radio, so I couldn't tell you what modifications you would need to make. If I had the radio in front of me I could do it. But I looked and cannot find a schematic diagram of this radio, so there is no way I can tell you how to do it.
However, if there is a CB shop in your area you can take it there. They will charge in the ball park of $30.
If you want to send it out, you can contact
http://www.bellscb.com/ and then send it to them, and they will peak and tune it. They are a good shop. Not sure what they will charge, and there is also shipping.
As for receive, there's not much you can do. It's all about your antenna. If you put a base antenna like an antron 99 in a tree and use an adapter to hook it to where the antenna goes, then you would have much better receive. As well that would also help you get out better. However the radio would be much less portable. But you could set one up at your home for when you use it at home, and just plug into it when you want.