Please help: permlink structure / 301 Redirect

Hello there!

I’d like to change the permalink structure and I know that there are various plugins out there who help to solve the 301 redirect problem, but I’d like to do this manually because I cannot get one plugin to work. (in detail: the new permalink structure works, but I get 404 errors because he redirect doesn’t work)

Now the problem is that I don’t know how to setup the 301 redirect in the .htaccess file. Maybe someone can help me to do this. I have full write access and I believe there are only two or three lines I have to add…?

Thanks for your help,
Bye