Vacuum lines typically can't be repaired only replaced.
Step 1. remove a section of line. (take to parts store)
1a may need to remove a hose clamp typically a flat blade screwdriver but sometimes a compression spring type that can be opened with pliers.
2. go to a local parts store.
3. get new vacuum line of same diameter (see step 1)
4. install new line (same way you removed it)

never remove all the lines at the same time, too hard to remember where they all go.