Balance redox reaction

The half equation for the oxidation of Mn2+(aq) to Mn(OH)3(s) in an alkaline medium is:
Mn2+(aq) + 3OH-(aq) → Mn(OH)3(s) + e- ...... (1)

The half equation for the reduction of O2(g) to OH-(aq) in an alkaline medium is:
O2(g) + 2H2O(l) + 4e- → 4OH-(aq) ...... (2)

(1)x4 + (2), and eliminate 4e‑- and 4OH-(aq) on both sides. The overall equation is:
4Mn2+(aq) + O2(g) + 8OH-(aq) + 2H2O(l) → 4Mn(OH)3(s)

can you have some steps, please??

4Mn2+ +6H2O+3O2+8e- -------->4Mn(OH)3