Disposal of Fully owned subsidiary

Hi, I would like to seek an advice on disposal of subsidiary:

P is holding , S is subsidiary:

If P has fully impaired the cost of investment in Sub S to 0, during the year, it would like to dispose the subsidiary at $2m.

S’s Net assets as follows:

Equity
Share capital 12m
Retained earning (10.5m )
Reserves 0.3 m
Equity 1.8m

In P’s co level, there will have gain on disposal of S for $2m. May I know what is the conso entry in group? Do I need to reverse $2m then compute the gain or loss on disposal of subsidiary in group level. Kindly advice on the consolidation entry.

Meantime, if I waive the debt owing by S $10, Net asset as follows:

Equity
Share capital 12m
Retained earning (0.5m )
Reserves 0.3 m
Equity 11.8m

What is the gain or loss on disposal of S? May I consult the conso adjustment?