Lync 2013 upgrade to Skype for Business with Hybrid (o365)

Hi,

I have to upgrade the Lync 2013 on-premise to Skype for Business 2015 with Hybrid (o365).

Scenario :-

I have one Standard Lync 2013 FE with Lync 2013 Edge and it is Hybrid with O365 Skype for Business.

some Lync users in on-premise and some users are in Hosted in Online 365 infra for Skype for Business.

Requirements:-

I want to upgrade the on-premise Lync 2013 Infra with skype for Business 2015.

query is :-

if I do in-place or parallelupgrade in on-premise lync 2013 infra to Skype for Business.

is any change requirement on Online O365 infra ?

Regards, Deepak