CHARAKARAKA
Saumya Ray Chaudhuri: I have gone through two articles which raised some questions in my mind. What is Swamsa?

You will find that the same results which JS described as looking from Swamsa are seen in BPHS by looking from Karakamsa. So Swamsa refers to points of Lagna, AK and Chandra in Navamsa per Sanjay teaching in London 2004. Karakamsa shows results which relate to your desires more while actualization is seen from Navamsa Lagna. Especially first and fifth are inborn abilities. This should be clear now.

Anil: When we do chara karak repalcement?

When planets are in the same degree then the charakarakas are replaced. The lower (antyakaraka) takes the position of the higher. So the lower position is empty now and that role of the lower Charakaraka is taken by Naisargika-karaka of CK. For example if Ju is AK and Me is AmK then Me will be AK and Ju (natural karaka fro AmK) will become AmK.
Anil:.In your horoscope , when we had done charakarak eplacement , why after the age of 33/34 mercury will act as AK. ( i mean why AK will be change again from up to Mer)?

2. In the natural age of the higher karaka the replacement is happening. So for Ju AK and Me AMK in the same degree it will happen in Ju age which is 33/34.