First, be very careful with any injections into the nose. The nose is very susceptible to color changes, discoloration, swelling, blood flow, pain, numbness, and other potential complications with inappropriate injections into the nose.
There isn't a filler on the market currently that is FDA approved for injection into the nose. Everything is being used off-label. Fillers should never be placed into the tip of the nose, since complications may more likely occur at the nasal tip. Fillers should only placed in the bridge to help smooth contour irregularities and to provide augmentation. Fillers which have been used for nonsurgical rhinoplasty include Radiesse and hyaluronic acids.
As other plastic surgeons have stated, collagen cannot be removed. Generally, one needs to wait several months for the body to naturally removed the injected collagen.
Depending on the specific anatomy of your nose and your desires, I suggest first speaking with a rhinoplasty surgeon who can use computer imaging to simulate rhinoplasty. You'll be able to visualize in real time what possibilities are potentially available. Only after a comprehensive in-person evaluation can a plastic surgeon help determine the appropriate options for you.
Dr. C