Can you change lookVector?

I made a script, and it had an error, someone on SH helped me, but now I realized that the front of the block, is not the front of the tool! Can I change the lookVector (subtract or add 90 degrees to it)? Here is my script

wait(1)
script.Parent.Equipped:connect(function(mouse)
    mouse.Button1Down:connect(function()
--	local animation = script.Slash
--	local plyr = script.Parent.Parent.Name
--	local char = workspace:FindFirstChild(plyr)
--	local anim = char.Humanoid:LoadAnimation(animation)
--	anim:Play()
	local bullet = Instance.new("Part")
	bullet.FormFactor = "Custom"
	bullet.Size = Vector3.new(0.5,0.2,0.2)
	bullet.BrickColor = BrickColor.new("Toothpaste")
	bullet.BackSurface = "SmoothNoOutlines"
	bullet.BottomSurface = "SmoothNoOutlines"
	bullet.FrontSurface = "SmoothNoOutlines"
	bullet.LeftSurface = "SmoothNoOutlines"
	bullet.RightSurface = "SmoothNoOutlines"
	bullet.Velocity = script.Parent.Part1.CFrame.lookVector * 100 --this part
	bullet.TopSurface = "SmoothNoOutlines"
	bullet.Parent = workspace
	bullet.Position = script.Parent.Handle.Position
	bullet.Transparency = 0
	bullet.CanCollide = true
	--local speed = script.Speed:clone()
	--speed.Parent = bullet
	local damage = script.DamageScript:clone()
	damage.Parent = bullet
	print("HALLAAA")
    end)
end)

Please help!!! Thank you!!!

partToRotate.CFrame = partToRotate.CFrame * CFrame.Angles(0, math.rad(90), 0) -- the y axis rotates the front of the part a certain ammount. Change 90 to -90 if it isnt the right direction.