I agree with everything mechanic said with this addition if I understand your original comments correctly as in going from a nickle than to a dime and then as you are doing back to a quarter you will be changing more components of the payout slide assemble other than just the slides as the coin tube, slide cover, posts, Etc. will need replacing and adjustments will be necessary for the horizontal slide release levers to be positioned correctly for proper slide releasing for payouts!
All these tasks are do-able if you have all the parts needed to accomplish the job, which you may have already and just not mentioned it!
Here below are some pictures that may be of help to you to understand the interaction between the payout slide assembly on the mechanism and the front jackpot assembly!
In the pictured example the main jackpot trip is brought about differently than yours as the post on the top slide alone, on the two pay slide, trips the main jackpot release!
There are 3 or 4 varieties of this interaction with all accomplishing the same task so you should probably be aware of this as you gather all the parts necessary to do what you wish to do!
Also as mechanic mentioned a strong led type flashlight of a smaller type can be used to keep from having to remove the upper casting if it is placed under the reel assembly slightly above and to the left of the clock fan to watch the interaction of the mechanism and the front jackpot!
Hope this helps somewhat!
Ciao,
MONTI