Recipe for Disaster
I cannot emphasize the need for caution, caution, and more caution with the path you're talking about taking. You are playing with fire, and you don't want to get burned. Proceed incredibly carefully, thinking about the worst possible situation (broke, divorced, unemployed, with pissed off ex-customers) before acting.
Four cups of perspective
Which is more important, your business or your relationship? That question is at the heart of whatever action you take. Since the two are intertwined, taking action on one will have impact on the other.
Add two tablespoons of preparation
Have you discussed this with your wife/partner at length? Have you spoken to your father? Do they understand what your opinion is? Do they have a different suggestion about the direction of the company? Is this something you can find a good compromise for?
Adults have discussions with other adults. Especially business associates and family members. If that isn't possible, you may want to address the core issue first, and then have a discussion about the business. It doesn't sound like the business will go under if you sort out more important issues first.
Let sit for 15 minutes
After you know what everyone thinks about the situation, think about the consequences of whatever action you take. To pilfer some of the solutions provided by nadyne:
Get a mediator or a couple's therapist, and work with them to figure out how to proceed
Realize that your wife may resent you using a therapist to get your way in a business decision. I know I would.
Just rewrite the front end without her permission
Realize that your wife may resent you acting unilaterally without their consent on the business side. I know I would.
Get her buy-off that she should formally sever ties with the company so that you can have the flexibility to do what is necessary for the future of your product
Realize that your wife may resent you asserting that this is your product/business when she owns 39%. I would too, especially if you had given me 49% of the company when you were of sound mind and body.
The point is that taking unilateral action without the preparation (discussing like adults and removing any barriers to that discussion first if they exist outside the context of this decision) will cause problems in your relationship. No offense, but it isn't really nice to do things unilaterally that impact other adults without consulting them about it first.
If you care about your relationship, which is the first thing you should be considering, it probably isn't a good thing to do not-nice things to your wife.
Let simmer at impossible heat for several years
Understanding all the above, and deciding "Damn the torpedoes, full speed ahead", realize that this can cause significant long-term issues both maritally, legally, and professionally. Be very sure you carefully review any contracts involving the creation of the company (specifically anything involving buying out partners, dissolution of the company, etc.). Consult with a lawyer (specifically a divorce attorney, to see what happens to the business in the case your spouse decides to be as spiteful as possible, for instance refusing to sell rights in the company and/or fighting to take ownership of the thing as part of the divorce case).
Heed that advice! The last thing you want to do is to go over your wife's head, make a change she resents, have her screw you over for it, and end up without your wife, without your business, and a bunch of pissed off ex-customers who aren't happy with how it ended up for them.
I can't tell you what decision to make (at the end of the day it is your choice), I can only suggest extreme caution before making it. Think long and hard about how you want your life to end up at the end of this, and make the appropriate decision based on what you discover.