windows 7 - merging a system partition with a partition preceding it

My hard drive is 500 Gb,

I partitioned it with 400gb for windows 7 and 100gb for Windows 10,

however I am in need of a bit more space, thus I shrank 50gb from the windwos 7 partition,

besides formatting and reinstalling Windows 10 (as a last option), how else can I expand the partition while keeping the current data?

Answer

Fond a solution,

using AOMEI Partition Manager, solved my problem

For those who are insterested

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