Hey Mairenimhadagain,
You can alter them with the product.
If you are using Paysuite if you go to the cog and then employer settings and then click on pension schemes, click on the name of the pension it will bring up a number of boxes. Employer and Employee contributions are two of the boxes and you can change the percentages in there
Any questions or if you are using the other payroll product let us know
Thanks
Emma