No it wouldn't be abrupt , it would be step wise process.
1.Ban Cow slaughter.
2.Enforce Uniform Civil Code.
3.Ban Burqa.
4.Ban brandishing religious symbols like skull cap. Sardar's Pagdi exempted.
5.Enforce POTA to check unrest.
6.Ban Madarsa , as they produce radicals.
7. Clamp down on population.Like socialist China.
8. Remove the word ' Secular '
from our preamble .
9. After a decade of step 8 when India becomes almost 10-12 Trillion $ economy. Declare from Red Fort that India has become Hindu Rashstra.