To link your Publishing & Master data, first click into the Work you want to link up to the relevant Asset(s).

From there, click into the Linked Assets tab.

You then have two options - either 'Add Asset' to link to existing Asset(s) in your account or 'Create Asset'

Using 'Create Asset' will re-use the title & lyrics and create a brand new Asset, automatically linking this Asset to the Work.

After that you can fill in the remaining Asset data as & when you desire.