how can I write to a texture buffer object?

I'm using a texture buffer object like that:

glGenBuffers(1, &tbo);
glBindBuffer(GL_TEXTURE_BUFFER, tbo);
glBufferData(GL_TEXTURE_BUFFER, maxSize*sizeof(float), faceNormals.data(), GL_STATIC_DRAW);
glGenTextures(1, &tbo_tex);
glBindBuffer(GL_TEXTURE_BUFFER, 0);

and I can read it inside my compute shader using texelFetch(u_tbo_tex, index), but how can I update this value?

thank you! luiz