Expat changing address - KITAP & KTP

As for KTP - Moving is pretty easy and mostly done as a one stop thing - My first move messing around took around three weeks, but my last change took a grand total of two visits to one office over three days, the second visit being to pick up the new card.
There's no need for an agent.

KITAS used to be easy if the new place is in the same immigration office area as the old, but I'm way too far out of date to know how things are at the moment.

Not complicated, first go to Ur new Banjar and ask for "Surat domicili", then bting It to imigrasi, they'll change the address on ur staty permit and with that go to Police, they will relase a report and finally go to civil office to get new KTP.
The alternative Is to pay and agent to do that, but check if the agent have the appropria unte license, a lot of freelance out there that can complicate Ur Life.