WANT TO CHANGE YOUR FUND'S SIP AMOUNT?

1. Obviously, the best way to increase SIPs is to activate a brand new SIP for the remaining months yourself - if the fund is still open for new SIPs - as you can then choose any of the allowed dates, including your existing date, as per your own convenience.
2. AMCs, too, intimate you about renewing existing SIPs in advance, when you can do the needful.
3. Also, check with the AMC if they have any regular provision to modify running SIPs.
4. As you will be activating a new SIP order technically, you can choose any of the allowed dates, including your existing date, as per your own investment convenience.
5. SIP amount can be reduced in various ways:-
a) In case of multi-date SIPs, cancel a few to reach your reduced amount.
b) If it's a single-date SIP, cancel it and start a new SIP with reduced amount, provided AMC is accepting new SIPs.
c) Check with AMC for any regular provision to modify running SIPs.
d) Specific SIPs can also be stopped through net banking, without any penalties or total cancellation, as SIP is a voluntary investing mechanism.
e) There may be marginal time lags before the final outcome too.
6. During emergencies, specific SIPs can also be stopped immediately through net banking, without any penalties or total cancellation, as SIP is a voluntary investing mechanism.
7. For direct cancellations on AMC websites online, time lag is only a couple of days for a DIY investor.
8. We can also reduce SIPs in a fund and continue, tailoring it to our needs, through multi-date SIPs in a month, instead of a single monthly SIP, and investing dynamically based on our own judgement, by monitoring the required amounts.
9. But we should do so without ignoring long-term goals, being the real aim of SIPs, especially for those investors who have earmarked a certain amount from their regular salary for achieving them.
10. We should also be clear about our overall annual investing pattern, unlike stocks - and earmark amounts and funds where we would like to do this - and not in already well-diversified funds meant for long-term retirement, education, big purchases, marriages, etc.
11. With EPFO now allowing 75% withdrawal after a month's job loss, long-term SIPs could be continued with this corpus too in the interim, till getting a new job, without putting undue stress on your emergency fund.
12. Having a step-up SIP approach will ensure that you keep pace with inflation and changes in your lifestyle over the years. 
13. While doing so, the overall asset allocation portfolio, linked to your goals and risk profile, shouldn't be allowed to go haywire.