If i do this and i want another time change the link, can i change it? ---Yes

Do i have to go to the website via directadmin then?--Login doesn't change.. just the logo link

I just like better to do it wia ftp or so, bacause i don't understand the injection, i am always scare to do something wrong.---Via FTP, you change the basic code and that affects, for example, the update, this solution does not, and if you want to change it, you can either edit it or delete it straight away