I don't know if there is a upgrade bin or exe file to which you can run and it will upgrade your agent.
Following will help you to configure 10.7 Agent as I instructed above.
Open your existing version agent profile file "/opt/CA/APM/10.5.x.x/IntroscopeAgent.profiles". and use same directives in 10.7 /opt/CA/APM/10.7.x.x/IntroscopeAgent.profiles file.
Also don't forget to update your AgentManager with MOM address.
After that open your application server console or Application startup file. and update JVM argument / startup file. you only need to replace 10.5.x.x with 10.7.x.x.
your Questions
Q: How about the old data.
A: Data is saved in Collectors Smartstor directory usually /data. so you are good because it is not saved in agent machines.
Q: And will the old data be mapped in the backend?
A: YES
Q: And what other files I have to configure?
A: Don't configure anything. 10.7 Agents are mature enough not to configure anything.
as soon as you will recycle your JVM the new logs will start saving in .....10.7.x.x/logs. if you want to check old logs you can find them ..../10.5/logs.
I hope it will help you a lot.
also www.wiki.ca.com/apm will also help you a lot to find the answers of yours questions.