FB Pixel is already put manually on my site. Can I safely switch to your plugin?

Hi.
I successfully have my Facebook Pixel installed on my site. The theme I’m using has a setting where I can put the script code into the Header (Header Scripts).

Can I safely activate your plugin and put the facebook pixel in your plugin?
In which order should I do this?
1) install plugin
2) delete pixel code from header in theme settings?
3) then activate your plugin and put the code where it needs to be (or follow the steps to put the pixel into your plugin… haven’t looked into this yet)

I want to avoid to mess up the working pixel.

Thanks for helping out.
Cheers