9 by 9 final centers help!

[LisztNZ]

Can someone give me an algorithm that will help me solve the 6 center pieces left on my 9*9*9.
Please help me as I am so close! I can solve all other centre pieces but the last ones on the middle slice won't work!
Does anyone know of an algorithm (s) for these?
Thanks

 

[Dene]

https://www.speedsolving.com/wiki/index.php/Niklas

 

[Berd]

Crazybadcuber has a video on it.