After Pentecost, How Did The Apostles Give The Holy Spirit?

Your question after pentecost must mean, after Acts 2, Acts 4 the Diciples the same ones who received the Spirits power to witness received fresh infilling during time of persecution. But you have good question,as the Acts continues phillip was preaching to many people and the scripture
says they received the word of God Acts 8 but a couple apostles wanted to check it out,my understanding is many were born again but paul and one his companions wanted to see if they
had received the Power (Dunamis) to preach and lay hands on sick, The book of Acts shows
that God does not do everything the same way, I think so we (believers) will not make any thing
a tradition or try to put God in a box on any thing. When Peter was was allowed to preach to
Cornelius and his house, the Holy Spirit fell while he yet speaking ,But in Acts19 1-5 acts records
they were already diciples but , ask them if they had received the Holy Spirit when first believed,
which I think he wanted to know if they recieved the Power ,just like the pentecost experiance.
HERE Paul laid his hands on them and acts records they spoke in tonques and phophesied.
So there is no one pattern we can hang our hat on. One thing always stays the same is
recieving Jesus as our Personal Saviour, by repentance and recieving his gift of pardon,
believing he is God in the flesh and physical resurrection.