Plugin Help PermissionEX rankups

I visited a few pages about how I could promote for example the VIP to MVP but I did not find anything to tell me how, so I was wondering if anyone could explain me how

*i nead that for the buycraft rankups*

my unfinished permission.yml
groups:
VIP:
options:
rank: '100'
default: true
prefix: '&8[&eVIP&8]&f '
suffix: ' &8»&f '
permissions:
- modify.world
- chatex.allowchat
- essentials.build
- essentials.signs.use.kit
- essentials.kit
- essentials.kits.basic
- essentials.kits.farmer
- essentials.kits.claim
- essentials.back.ondeath
- essentials.back
- essentials.spawn
- essentials.msg
- essentials.warp
- essentials.warp.list
- essentials.warps.*
- essentials.signs.use.buy
- essentials.signs.use.sell
- essentials.sell
- essentials.balance
- silkspawners.place.*
- kits.reload
- kits.sign
- essentials.tpa
- essentials.motd
- essentials.tpaccept
- essentials.tpdeny
- essentials.tpahere
- essentials.sethome
- essentials.delhome
- essentials.ignore
- essentials.home
- mycommand.cmd.13
- randomtp.tp
- mycommand.cmd.2
- mycommand.cmd.3
- mycommand.cmd.5
- mycommand.cmd.7
- mycommand.cmd.8
- mycommand.cmd.9
- mycommand.cmd.10
- mycommand.cmd.11
- mycommand.cmd.12
- trading.trade
- previewkit
MVP:
inheritance:
- member
options:
default: false
prefix: '&8[&3MVP&8]&f '
suffix: ' &8»&f '
permissions:
- previewkit
- essentials.hat

 

I think this is what you're looking for: https://github.com/PEXPlugins/PermissionsEx/wiki/Ranks-(Promotion-and-Demotion)