WRT1200AC v2 reallocate partition NAND

[Lovator]

Good afternoon, please tell me how to delete partitions mtd4 mtd5 kernel1 + rootfs1 (40 Mb),
mtd6 mtd7 kernel2+rootfs2 (40 MB)
and create mtd4 mtd5 kernel1+rootfs1 (80MB)
I want to get rid of the alternative partition because I don't use it.
i have usb to ttl cable and i can go into u-boot.

I found instructions, but they are not from my router and there is a different partition layout and I need to specify the correct blocks and partition sizes click

I will be very grateful if you help me with this task.

device nand0 , # parts = 10
#: name size offset mask_flags
0: uboot 0x000000200000 0x000000000000
1: u_env 0x000000040000 0x000000200000
2: s_env 0x000000040000 0x000000240000
3: devinfo 0x000000100000 0x000000900000
4: ubifs 0x000005000000 0x000000a00000
5: kernel 0x000002800000 0x000000a00000
6: rootfs 0x000002200000 0x000001000000
7: alt_kernel 0x000002800000 0x000003200000
8: alt_rootfs 0x000002200000 0x000003800000
9: syscfg 0x000002600000 0x000005a00000