Replace a larger HD in single disk environment (TS-251C)

My NAS is Qnap Ts-251C

I have installed two HDs
Slot1- HD1 - 1TB (system)
Slot2- HD2 - 3TB
Configured as two single disks

Now I want to replace HD1 with another new 3TB HD (HD3). (also configure as 2 single disks)

Can I perform in this way

Take out HD1, and clone HD1 to HD3 using ghost/acronis true
Plug HD3 into slot 1 of the NAS

Any better method ?

我想要睇你 舊1T hdd 是那一vol。 唔好亂來,問問 support 先