“It was not immediately clear how the debt would be reduced from its currently forecast level of 144pct in 2020 to the target of 124pct”

:-)

Followed by:

but it is expected to involve a series of measures including an extension of the maturity and lowering of interest rate on loans to Greece, a debt buyback and a return to Athens of profits made by the ECB on Greek debt it holds.

And no wonder that:

talks on the details of the debt cutting measures with the IMF were still ongoing.

Euro zone, IMF agree to cut Greek debt to 124 percent/GDP in 2020