Change size partition of windows in a already installed dual boot

I installed manjaro months a go in a notebook that already had windows installed. I make a dual boot.
But, now i want to increase the partition of manjaro and reduce the windows partition.
But, i remember that maybe you can corrupt the system in this operation, break the dual boot or something like that.
How i can do this without making damage? (or just rezising with gparted is the way to go?)

To shrink the active Windows partition
use Windows tools - do it from within Windows.

Then you can use gparted
to shift that freed-up space to linux

that will (probably, from what I know)
be able to extend the Linux partition
into the free space you just created.

You then have to extend the linux filesystem
to use that extra space.

All that is premised on that the two partitions are directly adjacent to each other.

gparted can show you

If that is not the case then this will not work.

In any case:
have a backup
… of both OS’s involved

error: unkown filesystem
entering rescue mode…
grub rescue>


If i make this:

set boot=(hd0,gpt4)
set prefix=(hd0,gpt4)/boot/grub
insmod normal

I can enter to the grub and to the operative system, but if i reboot… again the same.

sudo update-grub

After i try from a terminal that, but still i get grub rescue if reboot

and now
sudo grub-install /dev/sda2

and is again working fine, except that i cant extend the root partition

if you want to modify linux root partition, you have to do it from the live usb

ok, but i feel that if i do that i will damage the grub. Is like that? i mean i need to integrate the initial part of the partition.
I mean, i want to take the middle 16gb (sda6), and put that in sda4…
i have a live usb. So what i need to do to avoid damage the grub?

im not going to mess with your hard drive… but grub can be reinstalled if you damage it…
but if you damage windows bootloader by messing with partitions, you will have to reinstall it using windows iso, which will wipe manjaros grub, so you will have to reinstall it too…
also its possible that the uuids will change, so you will to address it too, by comparing blkid with fstab, and edit fstab to match blkid, if there are any differences in the uuid

And all continue with perfection!
Thanks! no error no, nothing. So, all good.